US5705750A - Ultrasonic sensor and pipetting apparatus using same - Google Patents

Ultrasonic sensor and pipetting apparatus using same Download PDF

Info

Publication number
US5705750A
US5705750A US08/617,951 US61795196A US5705750A US 5705750 A US5705750 A US 5705750A US 61795196 A US61795196 A US 61795196A US 5705750 A US5705750 A US 5705750A
Authority
US
United States
Prior art keywords
time
waves
reference point
phantom
waveform
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
US08/617,951
Other languages
English (en)
Inventor
Kazuaki Mizukami
Masashi Yasuda
Hiroaki Arakawa
Mikio Hojo
Toshihiko Matsuhashi
Yoshio Ozawa
Atsushi Ogawa
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sanyo Electric Co Ltd
Original Assignee
Sanyo Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP07083210A external-priority patent/JP3123895B2/ja
Priority claimed from JP30844595A external-priority patent/JP3573852B2/ja
Application filed by Sanyo Electric Co Ltd filed Critical Sanyo Electric Co Ltd
Assigned to SANYO ELECTRIC CO., LTD. reassignment SANYO ELECTRIC CO., LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: ARAKAWA, HIROAKI, HOJO, MIKIO, MATSUHASHI, TOSHIHIKO, MIZUKAMI, KAZUAKI, OGAWA, ATSUSHI, OZAWA, YOSHIO, YASUDA, MASASHI
Application granted granted Critical
Publication of US5705750A publication Critical patent/US5705750A/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N35/00—Automatic analysis not limited to methods or materials provided for in any single one of groups G01N1/00 - G01N33/00; Handling materials therefor
    • G01N35/10—Devices for transferring samples or any liquids to, in, or from, the analysis apparatus, e.g. suction devices, injection devices
    • G01N35/1009—Characterised by arrangements for controlling the aspiration or dispense of liquids
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
    • G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
    • G01F23/28—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring the variations of parameters of electromagnetic or acoustic waves applied directly to the liquid or fluent solid material
    • G01F23/296—Acoustic waves
    • G01F23/2962—Measuring transit time of reflected waves
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
    • G01S15/02—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems using reflection of acoustic waves
    • G01S15/06—Systems determining the position data of a target
    • G01S15/08—Systems for measuring distance only
    • G01S15/10—Systems for measuring distance only using transmission of interrupted, pulse-modulated waves
    • G01S15/101—Particularities of the measurement of distance
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N35/00—Automatic analysis not limited to methods or materials provided for in any single one of groups G01N1/00 - G01N33/00; Handling materials therefor
    • G01N35/10—Devices for transferring samples or any liquids to, in, or from, the analysis apparatus, e.g. suction devices, injection devices
    • G01N35/1009—Characterised by arrangements for controlling the aspiration or dispense of liquids
    • G01N2035/1025—Fluid level sensing
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/02—Indexing codes associated with the analysed material
    • G01N2291/028—Material parameters
    • G01N2291/02836—Flow rate, liquid level
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
    • G01S15/02—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems using reflection of acoustic waves
    • G01S15/06—Systems determining the position data of a target
    • G01S15/08—Systems for measuring distance only
    • G01S15/10—Systems for measuring distance only using transmission of interrupted, pulse-modulated waves
    • G01S15/102—Systems for measuring distance only using transmission of interrupted, pulse-modulated waves using transmission of pulses having some particular characteristics
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
    • G01S15/88—Sonar systems specially adapted for specific applications
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/52—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S15/00
    • G01S7/523—Details of pulse systems
    • G01S7/526—Receivers
    • G01S7/527—Extracting wanted echo signals

Definitions

  • the present invention relates to ultrasonic sensors for measuring distances and pipetting apparatus for pipetting or diluting reagents, samples and the like.
  • pipetting apparatus generally comprise a triaxially drivable table mechanism 18 controllable by a controller 19 and having a pipette head 15 attached to the output portion of the mechanism. Projecting downward from the head 15 is a pipette 16 for drawing in and discharging a reagent.
  • the pipette head 15 is moved by the operation of the table mechanism 18 to bring the lower end of the pipette 16 close to the cavity 21 in the plate 20, and the reagent is transferred from the pipette 16 into the cavity 21.
  • the reagent is to be added dropwise to other reagent 22 already placed in the cavity 21 for dilution or mixing, the reagent to be applied from the pipette 16 is brought into contact with the liquid surface of the reagent 22 in the cavity 21 to free the surface tension and thereby draw off the reagent from the pipette 16.
  • the pipette head 15 When the reagent is added for dilution or mixing, the pipette head 15 is lowered under the control of the controller 19 to bring the pipette 16 close to the liquid surface of the reagent 22 within the cavity 21 of the plate 20 to the greatest possible extent as stated above.
  • the liquid level of the reagent 22 differs from cavity to cavity, there arises a need to measure the liquid level every time to adjust the level of the pipette 16.
  • the measurement of liquid level of the reagent 22 requires an accuracy of the order of 0.1 mm.
  • the instrument is not usable for transparent reagents or reagents which are likely to undergo photochemical reaction since the reagent is irradiated with a laser beam in this case. Further because the liquid surface has irregularities due to surface tension, the direction of reflection is not definite, and the instrument has a problem with respect to sensitivity in receiving reflected light waves.
  • the ultrasonic sensor 1 emits waves toward the object of measurement, receives the waves returning upon reflection at the object and measures the time from the emission of the waves and receiving of the reflected waves to determine the distance to the object based on the measurement.
  • the transmitted waves have such a waveform that the amplitude gradually increases first and thereafter gradually decreases as seen in FIG. 14.
  • the received waves are also similarly shaped.
  • the received waves have the same frequency as the transmitted waves, and in peak value, a plurality of waves included in the received waves have a constant attenuation ratio to the corresponding waves included in the transmitted waves.
  • the time from the emission of the transmitted waves to the receiving of the received waves must be measured for the period from the rise of the first of the transmitted waves to the rise of the first of the received waves.
  • the time when the amplitude of the waveform has exceeded a predetermined threshold level is taken as the time of rise of the first of the received waves as shown in FIG. 14.
  • the measurement obtained by the conventional ultrasonic sensor involves an error corresponding to several wavelengths of ultrasonic waves.
  • the size of received waves varies with variations in the distance to be measured and with the planarity of surface of the object, consequently altering the point of time when the threshold level is exceeded. Accordingly, the above-mentioned error differs for different sizes of received waves.
  • the error may be minimized by increasing the frequency of the transducer, but this results in marked attenuation of the amplitude during the propagation of ultrasonic waves and impaired measuring sensitivity.
  • An object of the present invention is to provide ultrasonic sensors adapted to give measurements with high accuracy even with use of ultrasonic waves of relatively low frequency, and pipetting apparatus equipped with the ultrasonic sensor.
  • the present invention provides a first ultrasonic sensor comprising first detecting means for detecting the time of rise of the first of transmitted waves, second detecting means for detecting a plurality of peak points appearing in the waveform of received waves and detecting a waveform reference point where the time-base coordinate is a minimum on a phantom envelope connecting the peak points, and calculating means for calculating the distance to an object of measurement based on the time of rise of the first of the transmitted waves detected by the first detecting means, the time of the waveform reference point of the received waves detected by the second detecting means and a predetermined period of offset time.
  • the time of rise of the first of the transmitted waves can be detected based on the time when supply of drive pulses to the transducer is started.
  • the time Ps of rise of the first of the received waves is, as shown in FIG. 3, the time when a predetermined period of offset time To has elapsed from a waveform reference point Pb where the time-base coordinate is a minimum on a phantom envelope connecting a plurality of peak points Po appearing in the waveform of the received waves. Since any wave included in the waveform attenuates with the same attenuation ratio, phantom envelopes each connecting peak points Po extend through the same waveform reference point Pb in view of the geometric relation involved, regardless of the extent of attenuation as indicated in broken lines in FIG. 4.
  • the period of time (offset time To) from the reference point Pb to the time Ps of rise of the first wave is constant regardless of the distance to the object of measurement. Accordingly, the offset time To can be predetermined by experiments as a value inherent in the sensor.
  • the waveform reference point is a zero cross point Pz where the phantom envelope intersects the zero level of the waveform as indicated in a broken line in FIG. 5.
  • the zero cross point Pz coincides with a point where the time-base coordinate is a minimum on the phantom envelope. Accordingly, the zero cross point Pz can be detected as the waveform reference point.
  • the second detecting means comprises sampling means for sampling the received waves at 2n times (a is an integer of at least 1) the frequency of the transmitted waves, extraction means for extracting a plurality of apparent peak points regarded as peaks from the received wave sampled points obtained by the sampling means, and detector means for detecting a waveform reference point where the time-base coordinate is a minimum on a phantom envelope connecting the plurality of apparent peak points of the received waves obtained by the extraction means.
  • the extraction means extracts the plurality of apparent peak points from the received wave sampled points obtained at a specified frequency, i.e., at 2n times (n is an integer of at least 1) the frequency of the transmitted waves.
  • the received waves have the same frequency as the transmitted waves and have true peak points Po the cycle of which is constant as shown in FIGS. 6 and 7, so that even if the apparent peak points P deviate from the true peak points Po as illustrated, the deviations ⁇ S in the time-base direction are equal for all waves.
  • the phantom envelope connecting the true peak points Po and the phantom envelope connecting the apparent peak points P extend through the same waveform reference point Pb.
  • n 1
  • the extraction means extracts all the received wave sampled points as apparent peak points
  • the detector means detects a waveform reference point where the time-base coordinate is a minimum on a phantom envelope connecting these sampled points.
  • the received waves are sampled at twice the frequency of the transmitted waves, so that if one of the sampled points coincides with the true peak point Po of one wave in FIG. 6, all the other sampled points will be the true peak points Po of the other waves. Further even if the sampled points deviate from the true peak points Po, the deviations in the time-base direction of all the sampled points are equal as previously stated. Accordingly, the waveform reference point can be determined from the phantom envelope connecting these sampled points, i.e., the apparent peak points P.
  • n is, for example, at least 2
  • the extraction means compares the sampled points of the received waves with one another and extracts a plurality of apparent peak points which are regarded as peaks
  • the detector means detects a waveform reference point where the time-base coordinate is a minimum on a phantom envelope connecting these apparent peak points.
  • sampled points which are different in deviation with respect to the time-base direction will repeatedly occur with the cycle of the received waves as shown in FIG. 7, whereas if a plurality of apparent peak points P are extracted from these sampled points, the deviations ⁇ S of these apparent peak points P in the time-base direction are equal. Accordingly, the waveform reference point can be determined from a phantom envelope connecting these apparent peak points P.
  • the present invention provides a second ultrasonic sensor comprising detecting means for detecting a plurality of peaks appearing in each of the waveforms of transmitted waves and received waves and detecting a waveform reference point where the time-base coordinate is a minimum on a phantom envelope connecting the peak points of each waveform, first calculating means for calculating the elapsed time from the waveform reference point of the transmitted waves to the waveform reference point of the received waves, and second calculating means for calculating the distance to an object of measurement based on the time value calculated by the first calculating means.
  • the reference point of each of the waveforms of the transmitted waves and the received waves is detected, and the elapsed time from the waveform reference point of the transmitted waves to the waveform reference point of the received waves is taken as the elapsed time from the time of rise of the first of the transmitted waves to the time of rise of the first of the received waves.
  • the period (period of offset time To) from time t1 of the waveform reference point of the transmitted waves to time T1 of rise of the first transmitted wave is equal to the period (period of offset time To) from time t2 of the waveform reference point of the received waves to time T2 of rise of the first received wave, as will be apparent geometrically.
  • the elapsed time ⁇ T' from the waveform reference point of the transmitted waves to the waveform reference point of the received waves is in match with the elapsed time ⁇ T from the time of rise of the first of the transmitted waves to the time of rise of the first of the received waves.
  • the detecting means comprises sampling means for sampling the transmitted waves and the received waves at 2n times (n is an integer of at least 1) the frequency of the transmitted waves, extraction means for extracting apparent peak points regarded as peaks respectively from the transmitted wave sampled points and the received wave sampled points obtained by the sampling means, first detector means for detecting a waveform reference point where the time-base coordinate is a minimum on a phantom envelope connecting the apparent peak points of the transmitted waves obtained by the extraction means, and second detector means for detecting a waveform reference point where the time-base coordinate is a minimum on a phantom envelope connecting the apparent peak points of the received waves obtained by the extraction means.
  • n 1
  • the extraction means extracts all the sampled points of the transmitted waves and the received waves as apparent peak points
  • the first detector means and the second detector means each detect a waveform reference point where the time-base coordinate is a minimum on a phantom envelope connecting the sampled points of the corresponding waves.
  • the transmitted waves and the received waves are sampled at twice the frequency of the transmitted waves, so that even if one of the sampled points coincides with the true peak point Po of one wave and also if the sampled point deviates from the true peak point Po as shown in FIG. 6, the waveform reference point can be determined by the phantom envelope connecting the sampled points, i.e., the apparent peak points P.
  • n is, for example, at least 2
  • the extraction means compares the sampled points of each of the waveforms of the transmitted waves and the received waves with one another to extract apparent peak points regarded as peaks
  • the first detector means and the second detector means each detect a waveform reference point where the time-base coordinate is a minimum on a phantom envelope connecting the apparent peak points of the corresponding waves.
  • the elapsed time ⁇ T from the time of rise of the transmitted wave to the time of rise of the received wave shown in FIG. 14 is indirectly calculated. This eliminates the measurement errors inevitably involved in the conventional system.
  • the present invention further provides a pipetting apparatus which comprises the first ultrasonic sensor or second ultrasonic sensor of the invention installed, as directed downward, at one side of a pipette head.
  • the object of measurement by the ultrasonic sensor is the surface of a liquid placed in a cavity of a plate.
  • the distance to the liquid surface is calculated based on the time taken for the ultrasonic wave to reciprocatingly travel the distance from the sensor to the surface.
  • the ultrasolic sensor of the invention realizes accuracy of measurement not dependent on the wavelength of ultrasonic waves or the size of received waves and employs a measuring system which is free from errors in principle, consequently giving highly accurate measurements with a high resolution even with use of ultrasonic waves of relatively low frequency.
  • the pipette head can be positioned in place with high accuracy by virtue of the highly accurate measurement afforded by the sensor.
  • FIG. 1 is a block diagram showing the construction of an ultrasonic sensor embodying the invention
  • FIGS. 2(a) and 2(b) are waveform diagrams showing drive pulses and vibrations produced by a transducer, respectively;
  • FIG. 3 is a diagram for illustrating a waveform reference point where the time-base coordinate is a minimum on a phantom envelope
  • FIG. 4 is a diagram illustrating that the waveform reference point remains unchanged with variations in the attenuation ratio of the amplitude
  • FIG. 5 is a diagram illustrating a zero cross point
  • FIG. 6 is a diagram illustrating that the waveform reference point remains unchanged even when apparent peak points deviate from true peak points
  • FIG. 7 is a diagram illustrating the relation between true peak points and sampled points
  • FIG. 8 is a diagram illustrating the principle of calculation of a period of offset time
  • FIG. 9 is a flow chart showing a procedure for determining the distance to be measured.
  • FIG. 10 is a flow chart showing a procedure for determining the waveform reference point
  • FIG. 11 is a flow chart showing the first half of another procedure for determining the distance to be measured
  • FIG. 12 is a flow chart showing the second half of the same procedure
  • FIG. 13 is a flow chart showing a procedure for determining a waveform reference point in the case where the sampling frequency is twice the frequency of transmitted waves;
  • FIG. 14 is a diagram illustrating occurrence of a measuring error in the conventional system
  • FIG. 15 is a front view partly broken away and showing a pipetting apparatus embodying the invention.
  • FIG. 16 is an enlarged fragmentary view in section showing the pipetting apparatus
  • FIG. 17 is a diagram illustrating a method of calculating a period of offset time for use in the pipetting apparatus of the invention.
  • FIG. 18 is a front view partly broken away and showing a conventional pipetting apparatus.
  • FIG. 19 is an enlarged fragmentary view in section corresponding to FIG. 16 and showing the conventional apparatus.
  • FIG. 1 shows this embodiment, i.e., an ultrasonic sensor 1, wherein the operating mode of a transducer 2 is changed over to a transmitting mode or to a receiving mode by a change-over switch 3.
  • a clock pulse generator 4 feeds clock pulses of 400 kHz to a drive pulse generator 5 to prepare drive pulses of 400 kHz.
  • the drive pulses are amplified by an amplifier 6 and then supplied to the transducer 2 via the change-over switch 3.
  • FIG. 2(a) shows these several drive pulses which have a constant peak value, whereas the vibration produced by the transducer 2 assumes such a waveform that the amplitude gradually increases first and thereafter gradually decreases as seen in FIG. 2(b) owing to the mechanical impedance of the transducer 2.
  • the output of the amplifier 6 is fed also to a sampling circuit 12, and the signal thereby sampled is converted by an A/D converter 13 to digital data, which is fed to a microcomputer 25 by way of a bus line 14.
  • the microcomputer 25 has a timer 7, CPU 8 and memory 9 which operate based on reference clock pulses from a clock pulse generator 10.
  • the timer 7 is initiated into operation by a timer ON/OFF signal input thereto from the drive pulse generator 5.
  • the data forwarded from the A/D converter 13 via the bus line 14 is processed by the CPU 8, whereby the time of rise of the first of transmitted waves is detected.
  • the result is stored in the memory 9.
  • a suitably threshold level is set for sampling the waveform of received waves, such that the data below the threshold level in the absolute value of amplitude is excluded.
  • the microcomputer 25 thereafter detects a waveform reference point of the received waves to derive the time of rise the first of the received waves.
  • a waveform reference point Pb is the vertex of the curve where the time-base (-axis) coordinate of the curve is a minimum.
  • the time Ps of rise of the first of the received waves is the time when a predetermined period of offset time To has elapsed from the waveform reference point Pb.
  • any wave included in the waveform attenuates with the same attenuation ratio, phantom envelopes each connecting peak points extend through the same waveform reference point Pb in view of the geometic relation involved, regardless of the extent of attenuation as indicated in broken lines in FIG. 4.
  • the period of time (offset time To) from the waveform reference point Pb to the time Ps of rise of the first wave is constant regardless of the distance to the object of measurement. Accordingly, the offset time To can be predetermined by experiments as a value inherent in the sensor.
  • the distance L to the object is then calculated based on the elapsed time from the time of rise of the first of the transmitted waves to the time of rise of the first of the received waves.
  • the distance L to the object thus calculated is output by a printer or shown on a display as desired.
  • FIG. 9 shows the procedure starting with the generation of transmitted waves and ending with the calculation of the distance L to the object of measurement.
  • step S1 drive pulses are fed to the transducer 2 for the generation of transmitted waves, and in step S2, the time T1 of rise of the first transmitted wave is stored in the memory 9.
  • Step S3 subsequently performs sampling and A/D conversion of received waves, and the sampled data is stored in the memory 9 in step S4.
  • An inquiry is made in step S5 as to whether any data storage area still remains in the memory 9. If the answer is affirmative, the sequence returns to step S3.
  • Step S7 the ith data Di is retrieved from the memory 9.
  • Step S8 inquires whether the absolute value of the data Di is greater than the threshold level. When the answer to the inquiry is "No,” i is incremented, followed by step S7 again.
  • step S8 is followed by step S9, in which the time T2 of the waveform reference point of the received waves is derived.
  • the procedure of step S9 will be described specifically later.
  • step S10 the time T2 of rise of the first of the received waves is calculated from Equation 1 below based on the time t2 of the received wave reference point and the predetermined offset time To.
  • the offset time To which is a value inherent in the ultrasonic sensor 1, can be a specified value predetermined experimentally, whereas it is desired to calculate the value To every time for more accurate distance measurement.
  • the method of calculating the offset time will be described later in detail.
  • step S11 the elapsed time ⁇ T from the time T1 of rise of the first transmitted wave to the time T2 of rise of the first received wave is calculated from Equation 2 given below based on these times T1, T2.
  • a sound velocity c is calculated from Equation 3 given below in step S13.
  • tv is the temperature of air detected by a temperature sensor at the time of measurement. Since the sound velocity is thus dependent on the temperature, it is necessary to measure the temperature and calculate the sound velocity every time the distance is to be measured so as to ensure high accuracy.
  • step S9 i.e., the procedure for deriving the waveform reference point of the received waves.
  • the required counter variables n and m are reset in step S21 first, and the nth data item is retrieved from the memory 9 in step S22.
  • step S23 the absolute values of the nth, (n-1)th and (n-2)th data items are compared with one another, and if the absolute value of the (n-1)th is not a maximum, step S24 follows to increment n, whereupon the sequence returns to step S23.
  • step S25 follows, in which the (n-1)th data item is taken as the mth peak value.
  • step S26 the absolute value of the mth peak value is compared with that of the (m-1)th peak value. If the latter is smaller, step S27 follows to increment n and m. The sequence then returns to step S22.
  • step S29 is then calculated a point where the time-base coordinate is a minimum on the phantom envelope, i.e., a point (t2, V2) where the slope of the quadratic curve is zero.
  • This point can be determined as amplitude value V2 and time t2 satisfying Equation 5 below, and these values V2, t1 are given by Equations 6 and 7, respectively.
  • c is the sound velocity, which is calculated from Equation 3 in the same manner as in FIG. 9, step S12.
  • the foregoing procedure determines the time Te from the time T1 of rise of the first transmitted wave to the time t2 of the waveform reference point of the received waves, and the theoretical calculation gives the time Tr from the time T1 of rise of the first transmitted wave to time T2 of rise of the first received wave. Accordingly, the period from the received wave reference point t2 to the time T2 of rise of the first received wave, i.e., the offset time To, can be given from Equation 9 below based on the measurement Te and the theoretical value Tr.
  • the time T2 of rise of the receiving wave is calculated by adding the offset time To to the time t2 of the waveform reference point of the received waves in order to calculate the elapsed time ⁇ T from the time T1 of rise of the first transmitted wave to the time T2 of rise of the first received wave, whereas the same result is available by calculating the elapsed time ⁇ T' from the waveform reference point t1 of the received waves to the waveform reference point t2 of the transmitted waves.
  • the microcomputer 25 shown in FIG. 1 performs the same calculation procedure as in FIG. 10 for the sampled transmitted wave data supplied from the A/D converter 13 in the transmitting mode to detect the waveform reference point of the transmitted waves.
  • the reference point is the vertex of a quadratic curve as representation of a phantom envelope connecting a plurality of peak points appearing in the transmitted waves, i.e., a point where the time-base coordinate of the curve is a minimum.
  • the distance L to the object of measurement is then calculated based on the elapsed time ⁇ T' from the waveform reference point of the transmitted waves to the waveform reference point of the received waves.
  • the offset time To of transmitted waves is equal to the offset time To of received waves as geometrically apparent, so that the elapsed time ⁇ T' from the transmitted wave reference point t1 to the received wave reference point t2 is in match with the elapsed time from the time T1 of rise of the transmitted wave to the time T2 of rise of the received wave.
  • step S31 drive pulses are fed in step S31 to the transducer 2 for the generation of transmitted waves, followed by step S32 which samples the transmitted waves and received waves and effects A/D conversion.
  • step S33 the sampled data is stored in the memory 9 in step S33.
  • An inquiry is made in step S34 as to whether a data storage area remains in the memory 9. If the answer is affirmative, the sequence returns to step S32.
  • step S34 is followed by step S35, in which the counter variable i is reset.
  • step S36 the ith data is retrieved from the memory 9.
  • Step S37 inquires whether the absolute value of the data Di is greater than the threshold level. When the answer is negative, step S38 follows to increment count i, whereupon the sequence returns to step S36.
  • step S39 follows to derive the time t1 of the waveform reference point of the transmitted waves.
  • the reference point is derived by the procedure of FIG. 10.
  • step S42 inquires whether the emission of transmitted waves has been completed. If the answer to the inquiry of step S42 is negative, the sequence returns to step S41, whereas if the answer is affirmative, i is incremented in step S43.
  • step S45 The ith data Di is retrieved from the memory 9 in step S44, and an inquiry is made in step S45 as to whether the absolute value of the data Di is greater than the threshold level.
  • step S45 is followed by step S43 again, while if it is affirmative, the sequence advances to step S46, in which the time t2 of the waveform reference point of received waves is derived.
  • the reference point is derived by the procedure of FIG. 10.
  • step S47 the elapsed time ⁇ T' from the waveform reference point of the transmitted waves to the waveform reference point of the received waves is calculated from Equation 10 below based on the times t1, t2 of the transmitted and received wave reference points.
  • step S48 the sound velocity c is calculated from Equation 3 in the same manner as in FIG. 9, step S12.
  • step S49 the distance L to the object is calculated from Equation 11 given below, based on the elapsed time ⁇ T' from the transmitted wave reference point to the received wave reference point.
  • the ultrasonic sensor 1, according to the foregoing embodiment provides distance measurements with high accuracy and high sensitivity even with use of ultrasonic waves of relatively low frequency.
  • the waveform reference point is a point where the time-base coordinate is a minimum on the phantom envelope and is detectable independently of the voltage level, so that even if the ground level of the signal for detecting the waveform deviates from the center of amplitude of the waveform as indicated in a dot-and-dash line in FIG. 3, the detected position of the reference point remains unshifted free of any influence. Accordingly, the sensor provides measurements with high accuracy at all times and free from the error that would otherwise result from the deviation of the ground level.
  • the measurement obtained can be of higher accuracy.
  • FIG. 15 shows a pipetting apparatus equipped with the ultrasonic sensor 1.
  • the sensor 1 is attached as directed downward to an output portion of a triaxially drivable table mechanism 18.
  • the head and the sensor are always movable together by the operation of the table mechanism 18.
  • a tube 23 of circular cross section is attached vertically to the wave emitting portion of the sensor 1.
  • the tube 23 has the same inside diameter (about 7 mm) as cavities 21 in a plate 20.
  • the length of the tube 23 is 60 mm.
  • the liquid level of other reagent 22 already placed in the cavity 21 is measured first by the ultrasonic sensor 1.
  • the opening portion of the tube 23 is brought close to the opening portion of the cavity 21 of the plate 20 to the greatest possible extent to oppose the opening portions to each other in alignment as shown in FIG. 16.
  • the waves are guided by the inner peripheral surface of the tube 23 into the cavity 21 of the plate 20.
  • the waves are guided again by the inner peripheral surface of the tube 23 to return to the sensor 1.
  • the ultrasonic sensor 1 With the conventional pipetting apparatus wherein the ultrasonic sensor 1 is not provided with the tube 23, the ultrasonic waves emitted by the sensor 1 spead out as seen in FIG. 19. Some of the waves are projected onto the opening edge of the plate cavity 21, reflected from the edge and detected by the sensor 1. This entail the problem that an accurate measurement H is not available.
  • the wave channel of the tube 23 has a cross sectional shape identical or substantially identical with the shape of opening of the plate cavity 21, and the distance is measured with the opening portion of the tube 23 positioned close to the cavity 21 of the to the greatest possible extent as seen in FIG. 16. This eliminates the likelihood that some of the waves emitted by the sensor 1 will be projected onto the opening edge of the cavity 21, permitting all the waves to be guided into the cavity 21 and reflected from the surface of the liquid in the cavity 21.
  • the sensor 1 is caused to emit ultrasonic waves toward the flat portion of the plate 20 with the lower-end opening portion of the tube 23 in intimate contact with the flat portion.
  • the distance Ho from the wave emitting portion of the sensor 1 to the flat portion is equal to the length of the tube 23, which is known (i.e., 60 mm in the present embodiment). It is therefore possible to theoretically determine the period Tr, shown in FIG. 8, from the time T1 of rise of the first transmitted wave to the time T1 of rise of the first received wave.
  • the offset time To can be calculated by subtracting from the theoretical value Tr the measured value of the time, Te, from the time T1 of rise of the first transmitted wave to the time t2 of the received wave reference point.
  • the reference scale is unnecessary since the sensor 1 is positioned in place in this way by using the tube 23.
  • the measurement obtained by the sensor 1 is fed to a controller 19 shown in FIG. 15 for use in controlling the position of the pipette head 15.
  • the table mechanism 18 is operated based on the measurement provided by the sensor 1 to position the lower end face of the pipette 16 on the head 15 at a level 0.2 to 0.6 mm above the liquid surface of the reagent 22 in the plate cavity 21.
  • a plunger device (not shown) coupled to the pipette 16 is thereafter operated to discharge the reagent within the pipette 16.
  • the reagent to be drawn off from the pipette 16 contacts in the form of a drop with the liquid surface of the reagent 22 in the plate cavity 21 and is freed from surface tension, whereby the reagent is placed into the cavity dropwise.
  • the liquid level is measured by the ultrasonic sensor 1 with high accuracy. This accurately positions the pipette head 15 when the reagent is to be drawn off, obviating the likelihood of the other reagent adhering to the end face of the pipette 16.
  • the ultrasonic sensor 1 of the first embodiment is adapted to sample the amplitude value of transmitted waves and received waves at an optional constant frequency and to detect as a waveform reference point, the point where the time-base coordinate is a minimum on a phantom envelope connecting a plurality of peak points appearing in the received waves, whereas the ultrasonic sensor according to the present second embodiment is adapted to sample the amplitude value of waveform at 2n times (n is an integer of at least 1) the frequency of transmitted waves and to detect a waveform reference point where the time-base coordinate is a minimum on a phantom envelope connecting a plurality of apparent peak points appearing in the received waves
  • the sampling circuit 12 of FIG. 1 samples the waveform amplitude value at 2n times (n is an integer of at least 1) the frequency of the transmitted waves in the transmitting mode and the receiving mode.
  • the microcomputer 25 detects the waveform reference point of the received waves from the received wave sampled data supplied from the A/D converter 13 to derive the time of rise of the first received wave.
  • the waveform reference point Pb is the vertex of the curve where the time-base coordinate of the curve is a minimum.
  • the time Ps of rise of the first of the received waves is the time when a predetermined period of offset time To has elapsed from the waveform reference point Pb. Since any wave included in the waveform attenuates with the same attenuation ratio, the phantom envelope connecting the plurality of apparent peak points extends through the same waveform reference point Pb as a phantom envelope connecting true peak points in view of the geometric relation involved, so that the offset time To can be predetermined experimentally as a value inherent in the sensor.
  • the received waves have the same frequency as the transmitted waves and have true peak points Po the cycle of which is constant as shown in FIGS. 6 and 7. Therefore, even if the apparent peak points P deviate from the true peak points Po as illustrated, the deviations ⁇ S in the time-base direction are equal for all waves.
  • the phantom envelope connecting the true peak points Po and the phantom envelope connecting the apparent peak points P extend through the same waveform reference point.
  • the sampling frequency of the sampling circuit 12 is set at 2n times (n ⁇ 2) the frequency of the transmitted waves, sampled points which are different in deviation with respect to the time-base direction will repeatedly occur with the cycle of the received waves as shown in FIG. 7, whereas if a plurality of apparent peak points P are extracted from these sampled points, the deviations ⁇ S of these apparent peak points P in the time-base direction are equal. Accordingly, the waveform reference point can be determined from a phantom envelope connecting these apparent peak points P.
  • step S3 performs sampling at 2n times (n ⁇ 1) the frequency of the transmitted waves and A/D conversion.
  • the time t2 of the Waveform reference point of the received waves is derived in step S9.
  • the procedure for deriving the received wave reference point will be described in detail with reference to the case wherein the sampling frequency is twice the frequency of the transmitted waves.
  • step S51 the required counter variable n is reset first in step S51.
  • step S52 the nth data item is retrieved from the memory 9.
  • step S53 the absolute value of the nth data item is compared with that of the (n-1)th data item, and if the (n-1)th data item is smaller, n is incremented, followed by step S52 again.
  • step S56 is then calculated a point where the time-base coordinate is a minimum on the phantom envelope, i.e., a point (t2, V2) where the slope of the quadratic curve is zero.
  • This point can be determined as amplitude value V2 and time t2 satisfying Equation 5 previously given, and these values V2, t1 are given by the foregoing Equations 6 and 7, respectively.
  • the point (t2, V2) thus obtained is the waveform reference point, and the time t2 of the received wave reference point is derived.
  • the procedure to be performed is basically the same as is shown in FIG. 10 for the first embodiment.
  • the (n-1)th sampled point is taken as the mth apparent peak point in step S25 of FIG. 10.
  • the time T2 of rise of the first received wave is then calculated by adding the period of offset time To to the time t2 of the waveform reference point of the received waves, and the distance L to the object of measurement is calculated based on the elapsed time ⁇ T from the time of rise of the first transmitted wave to the time of rise of the first received wave.
  • the offset time To can be calculated by the method already described.
  • the distance L to the object can be calculated also based on the elapsed time ⁇ T' from the waveform reference point of the transmitted waves to that of the received waves.
  • the frequency at which the transmitted waves and received waves are sampled is related with the frequency of the transmitted waves, so that the waveform reference point can be derived even by sampling at a low frequency, for example, at two to 10 times the frequency of the transmitted waves.
  • the senor 1 of the present embodiment can be incorporated into a pipetting apparatus to achieve the same effect.
  • the waveform reference point is the vertex of a quadratic curve as representation of a phantom envelope connecting a plurality of peak points appearing in the received waves, i.e., the point where the time-base coordinate of the quadratic curve is a minimum
  • a phantom envelope connecting a plurality of peak points appearing in received waves is represented by a linear line, and the zero cross point where the line intersects the zero level of the waveform is taken as a waveform reference point.
  • the microcomputer 25 of FIG. 1 stores variations in the waveform in the memory 9 as data of two-dimensional coordinate system wherein the sampled time t is taken as the x-coordinate and the sampled amplitude value V as the y-coordinate. With the present embodiment, the data with negative y-coordinates is to be neglected.
  • the microcomputer 25 further detects the waveform reference point of received waves to derive the time of rise of the first of the received waves. As seen in FIG. 5, an envelope connecting peak points Po appearing in the received waves is represented by a linear line.
  • the waveform reference point Pz is then the zero cross point where the line intersects the zero level of the waveform, and the time when a predetermined period of offset time To has elapsed from the reference point Pz is taken as the time Ps of rise of the first of the received waves. Since any wave included in the waveform attenuates with the same ratio, the linear line extends through the same waveform reference point Pz regardless of the extent of attenuation, in view of the geometric relation involved. Thus, the period (offset time To) from the reference point Pz to the time Ps of rise of the first wave is constant regardless of the distance to the object of measurement. Accordingly, the offset time To can be predetermined experimentally as a value inherent in the sensor.
  • the time t2 of the waveform reference point of the received waves is derived in step S9.
  • the procedure for deriving the received wave reference point is basically the same as is shown in FIG. 10 for the first embodiment.
  • the nth, (n-1)th and (n-2)th data items are compared with one another in step S23, and the mth peak value is compared with (m-1)th peak value in step S26.
  • the zero cross point (t2, 0) provides a waveform reference point to derive the time t2 of the received wave reference point.
  • the time T2 of rise of the received wave is then calculated by adding the offset time To to the time t2 of the received wave reference point.
  • the distance L to the object is calculated based on the elapsed time ⁇ T from the time of rise of the first transmitted wave to the time of rise of the first received wave.
  • the offset time To can be calculated by the foregoing method.
  • the distance L to the object can be calculated also based on the elapsed time ⁇ T' from the waveform reference point of the transmitted waves to that of the received waves.
  • the ultrasonic sensor 1 of the present embodiment is useful when the ground level of the signal for detecting the waveform is not deviated from the center of amplitude of the waveform.
  • the senor 1 of the present embodiment can be incorporated into a pipetting apparatus to achieve the same effect.
  • the embodiments described are adapted to calculate the time of rise of the first received wave by adding the offset time to the time of the waveform reference point of the received waves, whereas it is possible to calculate first the elapsed time from the time of rise of the first transmitted wave to the received wave reference point and add the offset time to the result of the calculation.
  • the envelope can be approximated by two intersecting straight lines. In this case, the intersection provides a waveform reference point.
  • the positive data only is used according to the third embodiment, whereas the phantom envelope of transmitted or received waves can be obtained using the negative data in place of, or in addition to, the positive data. Furthermore, the phantom envelope can be approximated by a quadratic curve or exponential curve.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Health & Medical Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Thermal Sciences (AREA)
  • Fluid Mechanics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Electromagnetism (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)
  • Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
US08/617,951 1995-03-15 1996-03-13 Ultrasonic sensor and pipetting apparatus using same Expired - Fee Related US5705750A (en)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
JP7-083210 1995-03-15
JP07083210A JP3123895B2 (ja) 1995-03-15 1995-03-15 超音波センサ及びこれを用いた分注装置
JP7-308445 1995-10-31
JP30844695 1995-10-31
JP30844595A JP3573852B2 (ja) 1995-10-31 1995-10-31 超音波センサ及びこれを用いた分注装置
JP7-308446 1995-10-31

Publications (1)

Publication Number Publication Date
US5705750A true US5705750A (en) 1998-01-06

Family

ID=27304154

Family Applications (1)

Application Number Title Priority Date Filing Date
US08/617,951 Expired - Fee Related US5705750A (en) 1995-03-15 1996-03-13 Ultrasonic sensor and pipetting apparatus using same

Country Status (3)

Country Link
US (1) US5705750A (fr)
EP (1) EP0732598B1 (fr)
DE (1) DE69612777T2 (fr)

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5880364A (en) * 1997-10-31 1999-03-09 Cosense, Inc. Non-contact ultrasonic micromeasurement system
DE19816568A1 (de) * 1998-04-15 1999-11-04 Bosch Gmbh Robert Sensoranordnung zur Erfassung eines Drehmoments und/oder eines Drehwinkels
WO2000023815A1 (fr) * 1998-10-16 2000-04-27 Intersense, Inc. Systeme de mesure de distance
US20050095723A1 (en) * 2003-11-04 2005-05-05 Drummond Scientific Company Automatic precision non-contact open-loop fluid dispensing
US20070012113A1 (en) * 2005-07-18 2007-01-18 Helicos Biosciences Corporation Non-contact detection
US20070135057A1 (en) * 2005-12-09 2007-06-14 Nallapureddy Bhaskar V Detection and estimation of radio frequency variations
US20070274159A1 (en) * 2006-05-25 2007-11-29 Aisin Seiki Kabushiki Kaisha Obstacle detection device and method for estimating receiving time
DE102008009626A1 (de) 2008-02-18 2009-08-27 Advalytix Ag Verfahren zur Zustandsüberprüfung einer Pipette, Pipettierverfahren, Pipettiervorrichtung und Saugrohr für eine Pipettiervorrichtung
EP2098884A1 (fr) * 2008-03-05 2009-09-09 Siemens Milltronics Process Instruments Inc. Procédé d'identification d'un écho principal dans un système de mesure sonique
DE102008019991A1 (de) * 2008-04-21 2009-10-29 Mib Gmbh Messtechnik Und Industrieberatung Konzentrationsbestimmungsverfahren und Messgerät
US20100077853A1 (en) * 2007-03-30 2010-04-01 Roche Diagnostics Operations, Inc. Method and apparatus for detecting contact of a pipetting needle with a liquid in a vessel
US7834800B1 (en) 2006-06-29 2010-11-16 Marvell International Ltd. Systems and methods for detecting radar
CN1867813B (zh) * 2003-10-14 2011-01-26 洛德公司 用于测量距离的磁致伸缩传感器
US8643537B2 (en) 2010-10-18 2014-02-04 Siemens Aktiengesellschaft Method for processing an echo amplitude profile generated by a pulse-echo ranging system
US20150135838A1 (en) * 2013-11-21 2015-05-21 Industry-Academic Cooperation Foundation, Yonsei University Method and apparatus for detecting an envelope for ultrasonic signals
US10281370B2 (en) * 2016-04-26 2019-05-07 Taigen Bioscience Corporation Syringe assembly and method of using the same
US11415589B2 (en) 2018-03-14 2022-08-16 Hitachi High-Tech Corporation Automatic analyzer
US11499939B2 (en) 2017-10-04 2022-11-15 Ueda Japan Radio Co., Ltd. Ultrasonic wave transmitter, propagation time measurement device, gas concentration measurement device, propagation time measurement program, and propagation time measurement method

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6265676B1 (en) * 1997-03-10 2001-07-24 Electronics For Imaging, Inc. Systems and processing algorithms for ultrasound time-of-flight digitizer systems
US6331437B1 (en) * 1998-07-14 2001-12-18 Bayer Corporation Automatic handler for feeding containers into and out of an analytical instrument
AU777102B2 (en) * 2000-01-13 2004-09-30 Ortho-Clinical Diagnostics, Inc. Failure detection in automated clinical analyzers
DE10140346B4 (de) * 2001-08-17 2012-04-26 Robert Bosch Gmbh Verfahren zur Entfernungsmessung
US7925392B2 (en) 2002-04-23 2011-04-12 Lord Corporation Aircraft vehicular propulsion system monitoring device and method
US9086396B2 (en) 2008-11-28 2015-07-21 Roche Molecular Systems, Inc. System and method for the automated processing of fluids, method for determining the matching of objects
CN108156729A (zh) * 2017-12-06 2018-06-12 北京小米移动软件有限公司 照明设备、照明设备的控制方法及装置
US11543269B2 (en) 2020-01-27 2023-01-03 Temposonics GmbH & Co. KG Target detection in magnetostrictive sensors using a target frequency range

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4022058A (en) * 1975-08-07 1977-05-10 Brown Alvin E Apparatus for determining the arrival time of alternating signals
US4455556A (en) * 1980-05-19 1984-06-19 Nippon Electric Co., Ltd. Distance measuring equipment
US4480485A (en) * 1982-10-01 1984-11-06 Panametrics, Inc. Acoustic flowmeter with envelope midpoint tracking
WO1988002124A1 (fr) * 1986-09-16 1988-03-24 Bost & Co. Aktiebolag Procede d'indication du moment d'une impulsion acoustique et dispositif pour la mise en oeuvre du procede
US4750584A (en) * 1985-01-18 1988-06-14 Nippon Soken, Inc. Distance measuring device
US5206838A (en) * 1991-07-29 1993-04-27 Tokimec Inc. Ultrasonic transducer
WO1993025914A1 (fr) * 1992-06-08 1993-12-23 Behring Diagnostics, Inc. Systeme de distribution de liquides
US5428997A (en) * 1992-07-20 1995-07-04 Pasteur Sanofi Diagnostics Method of and device for fluid surface detection using an ultrasonic transducer
US5557047A (en) * 1993-02-10 1996-09-17 Fuji Ultrasonic Engineering Co., Ltd. Method and apparatus for ultrasonic wave measurement

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4022058A (en) * 1975-08-07 1977-05-10 Brown Alvin E Apparatus for determining the arrival time of alternating signals
US4455556A (en) * 1980-05-19 1984-06-19 Nippon Electric Co., Ltd. Distance measuring equipment
US4480485A (en) * 1982-10-01 1984-11-06 Panametrics, Inc. Acoustic flowmeter with envelope midpoint tracking
US4750584A (en) * 1985-01-18 1988-06-14 Nippon Soken, Inc. Distance measuring device
WO1988002124A1 (fr) * 1986-09-16 1988-03-24 Bost & Co. Aktiebolag Procede d'indication du moment d'une impulsion acoustique et dispositif pour la mise en oeuvre du procede
US4933915A (en) * 1986-09-16 1990-06-12 Bostroem Jan I Method of indicating the time of an acoustic pulse and a device for carrying out the method
US5206838A (en) * 1991-07-29 1993-04-27 Tokimec Inc. Ultrasonic transducer
WO1993025914A1 (fr) * 1992-06-08 1993-12-23 Behring Diagnostics, Inc. Systeme de distribution de liquides
US5465629A (en) * 1992-06-08 1995-11-14 Behring Diagnostics Inc. Liquid dispensing system with acoustic sensing means
US5428997A (en) * 1992-07-20 1995-07-04 Pasteur Sanofi Diagnostics Method of and device for fluid surface detection using an ultrasonic transducer
US5557047A (en) * 1993-02-10 1996-09-17 Fuji Ultrasonic Engineering Co., Ltd. Method and apparatus for ultrasonic wave measurement

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999022993A2 (fr) * 1997-10-31 1999-05-14 Cosense, Inc. Systeme ultrasonore de microanalyse sans contact
WO1999022993A3 (fr) * 1997-10-31 1999-07-08 Naim Dam Systeme ultrasonore de microanalyse sans contact
US5880364A (en) * 1997-10-31 1999-03-09 Cosense, Inc. Non-contact ultrasonic micromeasurement system
DE19816568A1 (de) * 1998-04-15 1999-11-04 Bosch Gmbh Robert Sensoranordnung zur Erfassung eines Drehmoments und/oder eines Drehwinkels
WO2000023815A1 (fr) * 1998-10-16 2000-04-27 Intersense, Inc. Systeme de mesure de distance
US6314055B1 (en) * 1998-10-16 2001-11-06 Intersense, Inc. Range measuring system
CN1867813B (zh) * 2003-10-14 2011-01-26 洛德公司 用于测量距离的磁致伸缩传感器
US20050095723A1 (en) * 2003-11-04 2005-05-05 Drummond Scientific Company Automatic precision non-contact open-loop fluid dispensing
US20070012113A1 (en) * 2005-07-18 2007-01-18 Helicos Biosciences Corporation Non-contact detection
US20070135057A1 (en) * 2005-12-09 2007-06-14 Nallapureddy Bhaskar V Detection and estimation of radio frequency variations
US8781401B2 (en) 2005-12-09 2014-07-15 Marvell World Trade Ltd. Detection and estimation of radio frequency variations
US8346174B2 (en) 2005-12-09 2013-01-01 Marvell World Trade Ltd. Detection and estimation of radio frequency variations
US7747222B2 (en) * 2005-12-09 2010-06-29 Marvell World Trade Ltd. Detection and estimation of radio frequency variations
US20100264902A1 (en) * 2005-12-09 2010-10-21 Nallapureddy Bhaskar V Detection and estimation of radio frequency variations
US7417922B2 (en) * 2006-05-25 2008-08-26 Aisin Seiki Kabushiki Kaisha Obstacle detection device and method for estimating receiving time
US20070274159A1 (en) * 2006-05-25 2007-11-29 Aisin Seiki Kabushiki Kaisha Obstacle detection device and method for estimating receiving time
US7834800B1 (en) 2006-06-29 2010-11-16 Marvell International Ltd. Systems and methods for detecting radar
US20100077853A1 (en) * 2007-03-30 2010-04-01 Roche Diagnostics Operations, Inc. Method and apparatus for detecting contact of a pipetting needle with a liquid in a vessel
US8100007B2 (en) * 2007-03-30 2012-01-24 Roche Diagnostics Operations, Inc. Method and apparatus for detecting contact of a pipetting needle with a liquid in a vessel
DE102008009626A1 (de) 2008-02-18 2009-08-27 Advalytix Ag Verfahren zur Zustandsüberprüfung einer Pipette, Pipettierverfahren, Pipettiervorrichtung und Saugrohr für eine Pipettiervorrichtung
EP2098884A1 (fr) * 2008-03-05 2009-09-09 Siemens Milltronics Process Instruments Inc. Procédé d'identification d'un écho principal dans un système de mesure sonique
DE102008019991A1 (de) * 2008-04-21 2009-10-29 Mib Gmbh Messtechnik Und Industrieberatung Konzentrationsbestimmungsverfahren und Messgerät
DE102008019991B4 (de) * 2008-04-21 2015-10-22 Mib Gmbh Messtechnik Und Industrieberatung Konzentrationsbestimmungsverfahren und Messgerät
US8643537B2 (en) 2010-10-18 2014-02-04 Siemens Aktiengesellschaft Method for processing an echo amplitude profile generated by a pulse-echo ranging system
US20150135838A1 (en) * 2013-11-21 2015-05-21 Industry-Academic Cooperation Foundation, Yonsei University Method and apparatus for detecting an envelope for ultrasonic signals
US9506896B2 (en) * 2013-11-21 2016-11-29 Industry-Academic Cooperation Foundation, Yonsei University Method and apparatus for detecting an envelope for ultrasonic signals
US10281370B2 (en) * 2016-04-26 2019-05-07 Taigen Bioscience Corporation Syringe assembly and method of using the same
US11499939B2 (en) 2017-10-04 2022-11-15 Ueda Japan Radio Co., Ltd. Ultrasonic wave transmitter, propagation time measurement device, gas concentration measurement device, propagation time measurement program, and propagation time measurement method
US11415589B2 (en) 2018-03-14 2022-08-16 Hitachi High-Tech Corporation Automatic analyzer

Also Published As

Publication number Publication date
EP0732598B1 (fr) 2001-05-16
DE69612777T2 (de) 2002-04-18
DE69612777D1 (de) 2001-06-21
EP0732598A1 (fr) 1996-09-18

Similar Documents

Publication Publication Date Title
US5705750A (en) Ultrasonic sensor and pipetting apparatus using same
US4210023A (en) Method and apparatus for measuring slag foaming using microwave lever meter
US4910717A (en) Apparatus for measuring distances
US4751689A (en) Method of measuring a distance
US5987994A (en) Ultrasonic method for material monitoring
US3380293A (en) Ultrasonic inspection apparatus
JP3547888B2 (ja) 超音波センサ及びこれを用いた分注装置
JP3123895B2 (ja) 超音波センサ及びこれを用いた分注装置
US6865137B2 (en) Method for pulse offset calibration in time of flight ranging systems
JP3573852B2 (ja) 超音波センサ及びこれを用いた分注装置
JP3117372B2 (ja) 超音波距離測定装置
JP3964946B2 (ja) 分注装置
JPH10332459A (ja) 液面検知方法
JPH08136643A (ja) 超音波距離測定装置
JPH04200539A (ja) 超音波探触子及び血流測定装置
KR0152725B1 (ko) 초음파를 이용한 거리 측정방법 및 측정장치
US20050281134A1 (en) Method and apparatus for pulse-by-pulse calibration of a pulse-echo ranging system
RU2171999C2 (ru) Способ определения параметров движения объекта локации и устройство для его осуществления
JPH0758179B2 (ja) クラッド厚さ測定装置
JPS6423106A (en) Measuring instrument for tread rest groove of tire
KR20020016008A (ko) 초음파 센서를 이용한 분체 레벨 측정 장치
JPH0712954A (ja) 地中埋設物探知方式及び装置
US5457395A (en) System and apparatus for measuring gaps between non-parallel surfaces
RU1778540C (ru) Ультразвуковой способ измерени уровн и устройство дл его осуществлени
JPH0526655A (ja) 膜厚測定方法及び装置

Legal Events

Date Code Title Description
AS Assignment

Owner name: SANYO ELECTRIC CO., LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:MIZUKAMI, KAZUAKI;YASUDA, MASASHI;ARAKAWA, HIROAKI;AND OTHERS;REEL/FRAME:007963/0969

Effective date: 19960415

FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8

REMI Maintenance fee reminder mailed
LAPS Lapse for failure to pay maintenance fees
STCH Information on status: patent discontinuation

Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362

FP Lapsed due to failure to pay maintenance fee

Effective date: 20100106